1. Field of the Disclosure
This disclosure relates to systems, methods and apparatus for fluid delivery. In particular, the present disclosure relates to valve systems that access refrigerant sources and the uses thereof for servicing refrigeration systems.
2. Description of the Related Art
Refrigeration systems have been relied upon as a principal source of cooling in a variety of applications. Refrigeration systems are found in, for example, vehicles, commercial buildings and residential buildings. Many refrigeration systems (e.g., air conditioning systems) use a circulating medium (e.g., refrigerant) that absorbs and removes heat from the space to be cooled and subsequently rejects the absorbed heat elsewhere.
Refrigeration systems operate based on principles of the Reversed Carnot Cycle, also known as the Vapor-Compression Refrigerant Cycle. The ability to achieve cooling by compressing and expanding a gaseous refrigerant may depend to some degree on the amount of liquid fluid present in the system. The amount of liquid fluid may directly influence the performance of vapor-compression-refrigeration systems.
Under charging the system of refrigerant may cause the system to not operate at design set points, risking shortened compressor life, poor cooling performance, and ultimately putting the compressor at risk of mechanical failure.
Over charging may cause liquid refrigerant to enter the compressor resulting in damage to the compressor, increased high side pressure putting more load on the compression system resulting in poorer energy efficiency along with increased wear on the compressor, higher pressures also can result in exceeding the refrigerant systems pressure safety limits and increasing compressor operating temperatures, both resulting in the system turning off and affecting overall cooling performance.
Several factors may adversely affect the amount of refrigerant in the system. For example, the refrigeration system may be subject to significant swings in temperature and frequent thermal cycling due to the action of the system itself and the heat produced by power sources (e.g., engines). Under these conditions, joints and fittings may tend to expand and contract, permitting refrigerant to slowly leak out of the system. In another example, the hoses used may be slightly permeable to the refrigerant, which may also permit the refrigerant to slowly leak out of the hoses. Accordingly, maintenance of refrigerant systems may require monitoring the refrigerant level or pressure and periodic re-charging of the refrigerant as indicated.
Typical automotive air conditioners are provided with at least one service port to allow for the monitoring of refrigerant level and addition of refrigerant to the system. U.S. Pat. No. 7,260,943 to Carrubba et al., which is incorporated herein by reference in its entirety, describes various apparatus that may allow measurements of the refrigerant pressure through a service port and to add refrigerant as needed.
The flow of refrigerant from the refrigerant source is typically regulated via a valve. In some instances, the refrigerant source is a can of refrigerant outfitted with a sealed can top (blind cap) that can only be accessed through the piercing of the seal. In this case, a valve is not part of the container and must be added to control the dispensing of the refrigerant. The valve is typically integrated within a servicing device which is threaded or otherwise attached to an outlet at a top end of the container (blind cap). In some instances, the servicing device includes a fixed length piercing member that is advanced as the servicing device is threaded onto the blind cap, piercing a hole in the seal, thereby allowing the pressurized refrigerant to be expelled from the can into the valve.
In certain refrigerant cans, an integrated valve (e.g., a self-sealing valve (SSV)) is provided at an outlet of the container. The SSV may include a spring-loaded piston that is biased to open the can when the piston is depressed and to close the can when the piston is released, thereby controlling the flow of the refrigerant. U.S. Patent Application Publication Nos. 2012/0192579 to Carrubba and 2011/0041522 to Carrubba describes servicing devices and adapters that are used for delivering refrigerant to refrigerant systems, all of which are incorporated herein by reference in their entirety.
These prior art methods and apparatus describe charging devices with an integrated valve for use on refrigerant cans that are equipped with either a blind cap or a SSV. However, there are no charging devices designed to access both types of refrigerant cans. Three inter-related design challenges exist hindering the development of a universal charging device that can open both types of can tops (i.e., blind cap and SSV).
With regard to the first design challenge, the two types of can tops are dimensional different requiring the piercing or plunging member to be of different lengths to open the refrigerant cans. Additionally, during the filling process, the refrigerant cans and can tops experience dimensional variances due to temperature and pressure changes experienced by the refrigerant. These dimensional variances impede the ability to activate the SSV or the blind cap after a positive seal is made between the charging device and the refrigerant can. A positive seal is required so that the refrigerant can contents are not released into the atmosphere.
The second design challenge is creating a component that is able to pierce a blind can top and depress the piston of an SSV while still allowing sufficient refrigerant flow.
The third design challenge is packaging the piercing/plunging component, valves, and seals capable of handling all of the potential dimensional variances in a low cost, simple, hand held package.
Accordingly, there is a need for devices that are able to be used with containers equipped with self-sealing valves and/or penetrable seals.
The present disclosure provides many advantages, which shall become apparent as described below.